Polyolefins can be prepared by polymerization of olefins in one or more reactors where feed materials such as diluent, monomer, comonomer and catalyst are introduced. The catalyst used can be sensitive to process impurities, or “poisons.” Thus, polyolefin production processes generally include treating reactor feeds to remove impurities prior to introduction of the feeds into the polymerization reactor(s). Techniques for treating reactor feeds include using a desiccant which traps the impurities. Over time, the desiccant can become saturated with impurities, creating a need for regeneration of the desiccant in order to maintain effective removal of the impurities. However, current regeneration processes can be costly, both in terms of nitrogen and fuel gas consumption, and in terms of the costs associated with regeneration times being longer than a month in some cases.